SEASONAL PRODUCTION OF ZOöPLANKTON OFF WOODS HOLE WITH SPECIAL REFERENCE TO CALANUS FINMARCHICUS'

• Main Authors: George L. Clarke, Donald, J. Zinn
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Fuller; Calanus finmarchicus; Copepods
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.133.5779; http://www.biolbull.org/cgi/reprint/73/3/464.pdf

The purpose of the work described in this paper was the investiga tion of the distribution of the plankton in the waters around Woods Hole during the summer months and the study of the seasonal changes in the plankton at one locality throughout an entire year. Our primary object specifically was to ascertain whether the copepod, Ccianus finmarchicus—a form used extensively for laboratory experi ments—breeds in this region, and if so during which months and with what success. It was proposed also to include measurements of the physical and chemical factors in the environment, and the collection of nannoplankton and phytoplankton, in order that the sequence of biological events from season to season in this locality might be followed. Cause and effect relationships in the growth of the various plankton forms might thus be unraveled. Since copepods play a prominent role in the economy of the sea, it is important to know what conditions promote their growth and what factors tend to reduce their numbers (Clarke, 1934). To this end a series of laboratory experiments was initiated in which the nutrition of copepods, particularly of CaJanus finmarchicus, was investigated (Clarke and Gellis, 1935; Fuller and Clarke, 1936; and Fuller, 1937). The nearest point from which copepods of this species could be obtained in sufficient numbers was in the deeper water off Gay Head. The population of Calanus at this locality was found to persist throughout the summer, but we had no knowledge either of the subsequent fate of these copepods or of the time and conditions of their appearance here. In our studies of nutrition we had assumed that the Calanus found in this area were living in equilibrium with their environment and that the smaller organisms found in the same body of water were adequate both qualitatively and quantitatively for their food supply. If, however, these copepods had been produced in another locality and transported hither by currents, the possibility existed that the conditions at our point of observation ...